| abstract |
Novel polyphenol compositions are prepared by successively reacting a phenol with formaldehyde or a reversible polymer thereof and sulfurizing the same with sulfur or a sulfur halide. The formaldehyde reaction and sulfurization may be effected in either order, but preferably the formaldehyde reaction takes place first. The resulting polyphenols are useful as oxidation inhibitors in lubricants. They may also be reacted with epoxides, and either the polyphenols or the epoxide reaction products thereof may be reacted with metal bases (especially alkali metal and alkaline earth metal bases, and preferably barium or calcium) to yield basic salts. The basic salts may also be reacted with epoxides, preferably ethylene oxide and propylene oxide. The basic salts thus obtained are useful in lubricants as detergents and oxidation inhibitors. |